Method of and apparatus for drawing glass.



APPLIGATOI SILED ICV. 9, 1908.

Patented July V12, 1910.

UNITED STATES PATEN T OFFICE.

ROBERT L. FRINK. GE CLEVELAND. OHIO.

METHOD OF AND APPARATUS POR DRAWING GLASS.

Application tiled November S, 1908.

Spetication of Letters Patent.

To all 'whom it may concern:

15o it known that. I, lonnnr L. Fiumi. a citizen of the United States, and a resident, of Cleveland, county of' Cuyahoga, and b'taie of Ohio, hare invented a new and useful Improvement in lvlethods of and Apparatus for lflrawinf-,f Glass, of which the following is a specilication, the principle of the invention being herein explained and the host mode in which l have contemplated applyingr that principle, so as to distinguish it from other inventions.

ln the drawing of glass cylinders as practiced in the art of manufacturing Window glass. it. has heretofore been too little appreciated what are thc relative etects of conduction, radiation and conrection in dc tei-mining the thickness and uniform character of the cylinder' walls` which ultimately, in their flattened form, provide the window glass of commerce. ll'hile the cooling of the metal both iu the drawing pot and in the cylinder' prior to setting may take on various important aspects, it is only with one of these that the present invent ion is concerned, namely, the coolingf of the. interior of the cylinder. while the walls of the latter are still in the plastic. stage in which they persist for some distance ahore thel level of the bath from which the cylinder rises. lt is not appreciated (in fact it may he questioned whether it is understood at all), that nuzch of the trouble encountered in the later course of nlanui'actm'e ot' window `glass may he traced hack dirutly to this portion of the operation. The large percentage of breakag -'c, in other words, that has heretofore attended the severing of the cylinders into lengths, the splittingr of thc-m prior to their introduction into the thun-uiucr oven, and the. tnal cutting. has heen accepted as one of the mysteries of the art rather than an object of scientific investigation and understanding. l am convinced. honorer, that practically all of auch breakage, aside from that duc to stratification, has its rise in unequal s.' rains produced in the walls of the cylinder hy the unequal cooling of the inner and outer faces thereof. l do not refer to inequality iu the rato of cooling between the two faces, since owing to the inner face heine' inclosed h v the walls it will naturally cool more slowly than the cuter face. but rather to zhose strains which arise when either the outer or the inner face. as the case may be, is subjected to variable cooling effects. at dirle-rent points longitudinally of the cylinder.

T he present invention has regard more particularly to controlling conditions of cooling within the cylinder by a proper regulation of the character of the fluid, whereby the cylinder walls are maintained inV proper distended form. To the accontplishmont .of this object. said invention then consists of the steps and embodies the means hereinafter fully described and particularly -pointed out in the claims.

The annexed drawing and the following description set forth in detail certain means and one mode of carryintr out the invention, such disclosed means and mode illustrating, however, but one of various ways in which the principle or the invention :nay be used.

In said annexed drawingzlfigure l is a vertical section. with parts shown in side elevation. of one approved arrangement of apparatus for carrying: out. my improved method of drawing glass; Fig. Q is a similar sectional riew, hut on a larger scale. of the drawing head utilized in connection with such apparatus; and Fig. 3 is a similar .'ertical section of a tank formingl another detail of the same apparatus.

Of that part of the plant designed for supplying the molten lass or metal. only that portion directly utilized in connection with the present apparatus is shown, viz.. the drawingT pot or receptacl.l A. The metal is supplied to said pot from the furnace (not shown) through a passage. or conduit A as will be readily understood. The particular' form of pot. so far as the purpose of the present inrcntiou is concerned. is u. matter of indifference. the illustrative construction shown being described and claimed in a cti-pendingl application tilt-t'. .lune 1li. 1908. Serial No. 39.7131 Similarlv the drawing mechanism propel' forms nu part of the present invention. being fully described in Letters Patent. No. 946.102, issued to me. March 190i'. Such mechanism, briefly described. 'will he seen to comprise a .Cet of rolls B hetween which the cylinder is pressed and drawn upwardly once i. has heen started. and an air regulating head B that. extends upwardly through an opening' In the. bottom of thel pot to a. short. distance above the contemplated level of inclten glass therein. namely. 1'ust below wherey the glass sets. T he general operation of the drawing.r mechanism involves the supply of air .through said head. there to be discharged into the lower confined portion of the cylin- `der being drawn, from whence it escapes which the cylinder. or hollow article, is,

l l l drawn. comprises two concentric pipes C C' t Figs. Q and 3, constructed of suitable material to resist'the temperature to which they are exposed when surrounded by the metal in the pot B. The head, which is supported on the upper ends of the aforesaid pipes, is

likewise constructed of suitable heat-rcsisting material, such as lire-clay or the like. The particular head here illustrated is .conical, or 'funnel-like. in form; and has a central aperture b therein, connected, as shown, with the-,inner C' of the two pipes of the support. ein the base of the head, there 1s formed an annular chamber b surrounding such central aperture, and provided with lateral orts b2, which chamber has communication withthe outermost C ot' the two pipes; Air under pressure is designed to be supplied at the head through such outer pipe and chamber, while on the contrary suction means are designed to be connected `with inner pipe, whereby a circulation of air may be maintained through the lower section of the cylinder or roller as indicated by the arrows in Fig. 2.

For supplying air to the cuter pipe and withdrawing it from the inner pipe, a blower or fan o is provided below the lower ends of such pipes, such fan being driven hy a suitable motor Ciwherehy any desired rate of circulation may he produced. Of the apparatus interpoacd between .this blower and theouter pipe t.. no detailed description uili here hc ne: sary, other than g L throughout the cylindcns length, hut also to state its ohject to be th., regulation of the volume ol' air admitted to the confined portion of the cylinder hy the use of suitable.

drawn as it is in the first instance from the portion of the cylinder adjacent to such conliued plastic portion, and where. the operation is under way, having passed through the phntic. still more highly heated portion, will he heated to an extent such as to a preciahly all'ect the temperature ofthe liquid n1 the tank. indeed it is contemplated that the latter may he liroughtJ ucar lo the boiling point. 'hcthcr such liquid he left thus. to attain its own equilibrium of temperature, or such temperature be artiticialhr controlled, it will hc obviousl that the air after p: .sing therethrough. will be of a substantially uniform teuqierature, and what is of more importance, possess a uniform degree of saturation, approxinmtely maximum satul l l l weighted escape valves l: c' connected with f a drnni C interposed in the discharge line connecting .said blower with such outer pipev interposed iu the other line of, however. viz., the one connecting thc inner pipe with the hlower, is a taule (l designed to contain fa; suitable liquid, orcferahly water, and of a capacity to he determined hy thc requirements hereinafter unlimited. The connection ol' the iuuer pipe with such tank, and

of thc .suction pipe f-` leading therefrom to the l'lower, is clearly indicated in lig. 3,

from which it will he seen that. the air sup- 5 plied to the drawinghcad through thc blower, j

is all drawn through the hotly of liquid contained in `uch tanlt'. lt is to this latter l'caturc that particular attention is' hert-in :lircctcd, namely. that1 of hluuidiying thc uit' which is supplied to thc drawing head, and is there utilized lo maintain tlupla-tic cylindcr walls properly distcndcd. 'this' air,

ration for the temperature in question. Such saturated air, as should he obvious, posscsses a greater capacity for :distracting heat from the roilcr than would dry air of the same temperature. this being due to the greater specific heat of water. One result hence, of my improved method of drawing glass, will he to secure an increased cooling cll'cct within the cylinder, so that the strata: in thc cylinder wall cooled from the exterior and interior, respectively, will be more nearly equal. .Xt the same time another result et' equally, it' not greater importance, is attained, namely, uniformity in such cooling. since the content or 'ater vapor carried h r the air may he controlled. Obviously, the more convenient mode of control is simply to secure lsaturation, since this is a constant; under lixed conditions-,of temperature and pressure. Y

vBy my improved method and apparatus I zuu enabled, accordingly, to produce a cylinder in which not only docs the internally cooled .stratum 'remain uniforni such stratum more nearly approaches inthickncss that of thc cxtcriorly cooled' stratum. au equality in auch thicknesses lieiug the idcal condition sought.

l :nu awartl that artilicial cooling ot' lmth the interior and cxtcrior surfaces of tht.l cylindcr has hccn attempted hy circulating :l liquid. as water, through coils disposed adjacent, to the rising cylinder walls. 'lhe impossibility. in practice, of obtaining uuil`orm rc-ults hy this method .should he rcadily evident aml sharply distinguishes the same from my methods ol' control. which involves the 'control ol' thc lsaturation ot` the, air and thus the ahsorption ol heat.

it will ol' course lm understood` that in place of tho particular drawing mechanism `shown. comprising thc drawing rollers ll llt) the drawing of glass whether such drawing be continuous or discontinuous, Moreover, So far as certain aspects of the method are concerned, it is immaterial whether the article being drawn be in the form of a sheet, or cylinder.

In conclusion. it. may be remarked that by seing the air through the liquid in tank a further incidental but quite important result is `secured, in addition to what has been previously noted. I refer to the working effect. on the air. whereby all dust. and like im urities. are eliminated and the diilicultv o s @cking or otherwise damaging the surface o the glass in its plastic. ilnpicssionable, state. bv such foreign matter overcome. Other modes of applying the principle of my invention may be employed inszead ot the one explained, change being made as regards the means and the steps herein disflosed, provided those stated by any one of the following claims or their equivalents be employed.

I therefore particularly tmint out and distinctly claim as my invention:

1. The method of producing lndiow glass articles, which consists in drawing acylinder Afrom a bath of molten glass, and maintaining therein a body of fluid havin a predetermined specific heat, substantially as described.

2. The method of producing hollow glass articles. which consists in drawing a cylinder from a bath of molten lass, and maintaining 1'herein a gaseous ody havinr a predetei .dined specific heat, substantially as cle(- scribed.

3. The method of producing hollow glass articles. which consists in drawing a cylinder from a hath of molten glass. and maintaining therein a bodly of air at a predetermined degree of humidity, substantially as described. '4. The method of producing hollow glass articles, which consists in drawing a cylinder from a bath of limiten-glass, and maintaining therein a body of fluid having an approximately constant specific heat, substantially as described.

5. The method of producing hollow glass articles, which consists in drawing a cylinder from a bath of molten glass, and maiutaining,y therein a gaseous body having an approximately constant specific heat, substantially described.

G. The method of producing hollow glass articles: which consists in drawing a cylinder from a bath of molten glass, andl maintaining therein a body of air having.r au

approximately constant degree of humidity, substantially as described.

7. The metnod of producing hollow glass articles, which consists in drawing a cylinder-.from a bat-h of molten glass, and

maintaining therein a body of au' approxit drawing ceases mately saturated with atery vapor., substantially as described.

S. The method of drawing hollow glass articles. which consists in drawingv a cylinder from a bath ot' molten glass: and introducing a Huid within said cylinder :unl confiningr the same below thc point where the glass sets. the action of such lluitln upon the cylinder being utilized to control its escape. and the tluifl thus ihtrotluced havin"r a prwletermincd Specific heat. substantially as described.

fl. The method of drawing hollow ,class articles. which consists in drawing a cyl' ulcr from a bath of molten glass; intrtnlucin; r air within said cylinder and continiug tho same below the point where the lla-s sus. the action of such air upon the cylinder bcing utilized to control it.- escape: :unl controlling thi` de rce of humidity of tht` air thin: introduced. substantially as described.

l0. The method of drawing hollow glas-A articlcs. which consists in drawingr a cylinder from a bath of molten glass-z intrmlucin; r air j within said cylinder and coufiniu; r the sannbelow the point where the glass sets. the action of .'-ruch air upon the cylinder bciu; r utilized to control its est-apc: and maintaining the degree of humidity of thc airthus introduced approximately constant. substantially as described. l

1i. The method'of drawing hollow glass articles. which consists in drawing a cylinder from a bath of molten glass: iutrmlucug air within said cylinder and confining the saunbelow the point where the glass sets', the action of such air upon the cylinder being utilized to control its escape: and maintaining.r the air thus introduced at approximately the point of Saturation with watery vapor, substantially as described.

1:2.' The method of cooling a glass artichbeing drawn from a hath of molten glass, which consists in bringing into contact with such article, afiuid having a predetermined specific heat, substantially as described.

13. The method ofjfooling a glass article being drawn from albath of molten glass. which consists iu bringing into contact with such article, a fluid having an approximately constant specific heat, substantially as dcscribed.

14. The method of coolingr a glass artic-lc bein; 7 drawn from a bath of molten glass. which con-:ists in bringing into contact with such article air haring au increased coutent of watery vapor` substantially as described.

15. lhe method of cooling a glass article boing drawn from .t bath of molten glass, wulch consists in liringingg` into contact with such article. air approximately saturated with watery vapor, substantially as described.

16. ln apparatus for drawingr glass, a

pot or receptacle, mechanism cooperative with said receptacle to dra cyltnder from molten glass therein. means for supplying z: fluid to the interior ofsuclt' cylinder, and means for controlling the specitic heat of the fluid thus' supplied.

.17. In apparatus for drawing glass. a drawing pot or receptacle. mechanism co- .operative with said receptacle to draw a cylmder from molten glass therein, tneans for supplying ail` to the interior of .such cylinder. and means for controlling the degree of humidity ofthe ai." thus supplied.

1S. In apparatus for drawing glass. t1 drawing pot or receptacle. mechanism cooperative with said receptacle to draw a cylinder trom molten glass therein. means for supplying air to the interior of auch cylinder. such means: including a duct connected with .such cylinder. and means` interposed in .said duct for.humidifying the air passing therethrough.

lhln apparatus for drawing glass, a

dttwing pot or receptacle. mechanism coopera! ire with .said receptacle to draw a. cylinder from molten glass. therein. means for suppl \'ing air to the interior of .such cylinder. .such means; including a ductl connected with .such cylinder. and a tank interposed in said duct, .said tank containing water through which .such air is passed, whereby .sut-h air is approximately .saturated with watery vapor.

.20. in apparatus for drawing'glass, a drawing pot or receptacle, mechanism eooperatiye. with .said receptacle ti draw a cylinder from molten glass therein. a head arontul which .sttch cylinder is drawn, an air-.supply`pipe .'unnected with .said head and a tank connected with .said pipe. .said tank containing water through which .such air is passed. whereby .such ait' is approximately .saturated with watery vapor.

2l. lu apparatus l'or drmt'ing glass. a drawing pot or reeept.tcle. titechanism cooperative with .said receptacle to draw a c vlinder from molten glass therein. a head around which .such cylinder is drawn. two pipes one within the other. for .supportiuf .said head :ttul opening. the one into tite po-r` tion of said cylinder hetween .said head and the hath. and the other into the. portion ot said cylinder above .said head. :ttul means adapted to withdraw air from .said cylinder through .such last-named pipe and return the .same through tlte lirslvitalued.

2;'. ln apparatus for drawing glass. a

al drawing pot or receptacle, mechanism eo'- operative with .said receptacle to draw a cylinder from moltenglass therein, a head around which such cvlinder is drawn, two pipes one within the other. for supporting .said head and opening. fhe'one into the portion of said-cylinder between said head and the bath` and the other into the portion of .said eylinder ahove said head. means adapt',` ed to withdraw air from said cylinder through .siueh last-named pipe and return the same through the tit'stdnttued. and means interposed in one of said pipes for hlttnidifying the air passing therethrough.

2i. ln apparatus for drawing glass, a drawing pot or receptacle, mechanism cooperative with vsaid receptacle to draw a cylinder from melted glass therein, a. head around which such cylinder is drawn, two pipes one within the other, for support-ing .said head and opening. the one into the portion of said cylinder between said head and the hath. and the. other into tite portion of .said cylinder above .said head. means atl-.1ptcd to withdraw air from said cylinder through .such last-named pipe and return the same through the lirst-named, and a. tank interposed in .said last-named pipe, said tank containing water. through which such air is passed, whereby such air is approximately .saturated with watery vapor.

24. In apparatus for drawing glass, a drawing pot or receptacle, mechanism oooperative with said receptacle to draw a cylinder from molten glass therein, a head around which .such cylinder is drawn, two pipes. one within the other for supporting .said head and opening, the one into the portion of .said cylinder between said head and the. hath. and the other into the portion of .said cylinder ahove .said head, a. blowe!` adapted to withdraw air from sttch last'- named pipe and to return 'the same through the lirst named. a tank interposed in sald last-named pipe. .said tank containing water through which such air is passed, whereb .such air is approximately saturated wit-g watery vapor. and means interposed in said tirst named pipe t'or regulating the volume of'airsupplied therethrough to said c linder. Signed by me this 23rd day of etober HUBERT L. FRlNK. .\ltc.sled ity- )lant- (t..\owt-:t.r., Jao. l". Ontstaan. 

